In addition to the names of taxpayers, authorities are seeking deposit or withdrawal amounts and taxpayer ID numbers

MEXICO CITY — Mexico is widening a probe into tax evasion by requiring banks to hand over names of local clients with transactions in tax havens, documents showed, weeks after the “Panama Papers” cast a spotlight on how the world’s rich and famous stash their wealth.

In a letter this year, Mexico’s Tax Administration Services (SAT) asked banking regulators to compel banks and brokerages to provide a list of clients who made transactions or investments in over 100 jurisdictions.

Offices of the Tax Administration System (SAT) located at Avenida Hidalgo 77 in Mexico City. Photo: Cuartoscuro/Moises Pablo

“To comply with its fiscal responsibilities over resident taxpayers with presumed financial assets in countries designated as ‘tax havens’, SAT … requires information and documentation to plan and schedule tax examinations of those taxpayers,” the letter said.

The date that the letter was sent was not able to be verified, but a source familiar with the matter said it was dated last month.

SAT and Mexico’s banking authority CNBV declined to comment.

Governments worldwide have begun cracking down on tax evasion since early April when reports based on an 11.5 million-document leak from Panamanian law firm Mossack Fonseca shed light on schemes used by the rich to skirt taxes.

SAT chief Aristóteles Núñez Sánchez said last month that authorities were investigating 33 people mentioned in the “Panama Papers” for possible tax evasion or financial crimes.

In a statement earlier this week, SAT said it would also probe people and companies named in a subsequent publication.

A separate letter from Mexico’s banking regulator to a brokerage asks the firm to comply with the massive information request in 15 working days. If it fails to comply, it could face fines or temporary closure, according to a law cited in the letter.

A source familiar with the matter said some banks received a similar letter last month.

Many of the jurisdictions listed in the letter from SAT, including Anguilla and Belize, are on the OECD’s 2000 tax haven list. But the list also includes Ireland and the U.S. states of Delaware and Nevada.

In addition to the names of taxpayers, authorities are seeking deposit or withdrawal amounts and taxpayer ID numbers.